The present invention is directed to an optical display device having a body preferably in a plate-shape which consists of a material having an index of refraction greater than 1 and has at least one character, symbol or the like which is in optical contrast with the background.
Display devices are being increasingly adopted for optically representing information of different kinds, for example, information concerning the operating state of an electrically controllable device. The displays required for this purpose are frequently used in mass produced articles such as program displays for washing machines or transmitter scales for radios and, therefore, require as simple as possible construction to supply a contrast of uniform quality. In addition, the symbol must also be readable from oblique directions and if additional illumination is required, this additional illumination should consume as little power as possible.